490
FXUS63 KDMX 180356
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1056 PM CDT SAT OCT 17 2026
...UPDATED FOR THE 06Z AVIATION DISCUSSION...
KEY MESSAGES
- THE FORECAST IS DRY THROUGH THE COMING WORK WEEK WITH SLOWLY
WARMING TEMPERATURES.
- A BIT BREEZY THROUGH SUNDAY, THOUGH NOT NEARLY AS MUCH AS IT
WAS ON SATURDAY.
- RAIN CHANCES AND MORE CHANGEABLE WEATHER CONDITIONS MAY RETURN
NEXT WEEKEND, BUT FORECAST DETAILS ARE STILL IN FLUX AT THIS
RANGE.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 128 PM CDT SAT OCT 17 2026
WE GOT OFF TO A COOL START THIS MORNING, WITH MUCH OF OUR
SERVICE AREA EXPERIENCING THE FIRST FREEZE OF THE SEASON. A FEW
STATIONS SUCH AS THE DES MOINES AIRPORT AND LAMONI REMAINED JUST
ABOVE FREEZING AROUND 34-35, BUT MOST OTHER STATIONS FELL TO 32
OR BELOW, AND IN MOST OF OUR NORTHERN AND WESTERN COUNTIES THE
TEMPERATURE FELL BELOW 30 DEGREES.
THE SURFACE RIDGE THAT WAS DRAPED ACROSS MUCH OF IOWA LAST
NIGHT IS SLIDING SOUTHEASTWARD TODAY, AND WILL RESIDE ROUGHLY
ALONG OR JUST NORTH OF THE OHIO RIVER VALLEY BY SUNDAY MORNING.
MEANWHILE, A BROAD LOW PRESSURE TROUGH IS FORMING ALONG THE LEE
OF THE ROCKIES, AND THE PRESSURE GRADIENT BETWEEN THE TROUGH AND
THE RIDGE WILL BE LOCATED MORE ACROSS OUR AREA FROM THIS
AFTERNOON THROUGH SUNDAY AFTERNOON. THIS WILL RESULT IN FRESH
SOUTH TO SOUTHWEST BREEZES DURING THAT TIME. TEMPERATURES WILL
REMAIN A BIT BELOW SEASONAL NORMALS THIS AFTERNOON, COMBINING
WITH THE BREEZES TO KEEP THINGS A BIT CHILLY OUTSIDE DESPITE THE
RESPLENDENT SUNSHINE. THE BREEZE WILL THEN HELP TEMPERATURES
STAY UP TONIGHT, WITH LOWS AROUND SUNRISE SUNDAY MORE IN THE
LOWER 40S OR SO THROUGHOUT OUR FORECAST AREA. HOWEVER, ANY MORE
SHELTERED SPOTS WHERE WINDS TO LIGHT OVERNIGHT MAY COOL INTO THE
MID/UPPER 30S. ON SUNDAY TEMPERATURES WILL REBOUND DUE TO
AIRMASS MODIFICATION, WITH HIGHS GENERALLY IN THE MID 60S MAKING
FOR A GLORIOUS AUTUMN DAY.
FROM SUNDAY NIGHT THROUGH MONDAY NIGHT THE SURFACE PATTERN WILL
LOOSEN UP, RESULTING IN LIGHTER WINDS. A BROAD HIGH PRESSURE
AREA WILL PERSIST TO OUR EAST, ROUGHLY OVER THE GREAT LAKES
REGION, WITH LIGHT SOUTHEASTERLY BREEZES IN OUR AREA ENTRAINING
DRY AIR OUT OF THAT RIDGE. DRY, CLEAR CONDITIONS WITH LIGHT
WINDS WILL SUPPORT A CONTINUED WARMING TREND DURING THE DAY, AND
GOOD COOLING CONDITIONS OVERNIGHT BUT AGAIN WITH A SLOW
MODIFICATION TREND CONTINUING. NBM TEMPERATURES IN THIS REGIME,
FROM SUNDAY THROUGH MONDAY NIGHT, ARE A BIT TOO LOW DURING THE
DAY AND A BIT TOO HIGH DURING THE NIGHT AS IT APPEARS TO BE
OVERDONE WITH ITS SURFACE HUMIDITY/DEWPOINTS. HAVE THUS
CONTINUED THE TREND OF BUMPING UP DAYTIME TEMPS AND BUMPING DOWN
NIGHTTIME TEMPS. THE RESULT IS MONDAY AFTERNOON HIGHS
APPROACHING 70 DEGREES IN OUR SOUTHEASTERN COUNTIES, WITH SUNDAY
NIGHT AND MONDAY NIGHT LOWS GENERALLY IN THE UPPER 30S TO MID
40S. ADDITIONAL FREEZES ARE NOT ANTICIPATED IN THE NEAR FUTURE.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED AT 128 PM CDT SAT OCT 17 2026
BY TUESDAY MORNING, A BROAD 500 MB HIGH PRESSURE RIDGE WILL BE
LOCATED OVER MOST OF THE CENTRAL AND EASTERN U.S. HOWEVER, A
WEAK SHORTWAVE WILL BE MOVING OFF THE ROCKIES AND OVER THE HIGH
PLAINS. THIS FEATURE WILL PASS SLOWLY NEAR IOWA ON TUESDAY INTO
WEDNESDAY, BRINGING SOME MID/HIGH LEVEL CLOUDS ACROSS THE REGION
DURING THAT TIME. A FEW MODEL SOLUTIONS EVEN ATTEMPT TO SPIT
OUT LIGHT RAINFALL, HOWEVER, FORECAST SOUNDINGS INDICATE
SUBSTANTIAL DRY AIR IN THE LOWER/NEAR-SURFACE LEVELS WITH FLOW
OUT OF THE GREAT LAKES RIDGE, WHICH SHOULD PRECLUDE ANY
MEANINGFUL CHANCES OF PRECIPITATION. MEANWHILE, DESPITE SOME
INCREASE IN CLOUD COVER, AIRMASS MODIFICATION SHOULD ALLOW FOR
CONTINUATION OF A SLOW WARMING TREND WITH TEMPERATURES PEAKING
IN THE LOWER 70S OR SO ON WEDNESDAY AFTERNOON.
FROM LATE WEDNESDAY INTO FRIDAY A MORE PRONOUNCED 500 MB RIDGE
WILL BUILD OVER THE CENTRAL U.S., INCLUDING IOWA, SUPPORTING
CONTINUED DRY WEATHER AND SLOW WARMING. HIGHS IN THE 70S ARE
FORECAST BOTH THURSDAY AND FRIDAY. EVENTUALLY, BY THE END OF THE
WEEK, A DEEP 500 MB TROUGH WILL MOVE INTO THE WESTERN U.S.
ROCKIES AND BRING A RETURN OF MORE CHANGEABLE WEATHER AND SOME
RAIN CHANCES BY NEXT WEEKEND. ANY DETAILS OF TIMING/LOCATION OF
RAIN CHANCES AND OTHER SENSIBLE WEATHER FIELDS ARE STILL IN FLUX
AT THIS RANGE, BUT WILL STEADILY COME INTO BETTER FOCUS AS THIS
WEEK PROGRESSES.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1054 PM CDT SAT OCT 17 2026
VFR CONDITIONS TO PREVAIL THROUGH THE PERIOD. LLWS LIKELY FOR
KMCW AND KFOD TONIGHT, WITH MARGINAL LLWS AT KDSM BEFORE
SUNRISE. HAVE LEFT OUT OF TAF DUE TO LOW MAGNITUDE. SOUTHWEST
WINDS WILL BE COMMON WITH GUSTS AROUND 20KTS.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM...LEE
LONG TERM...LEE
AVIATION...JIMENEZ
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page